diff --git a/customext/cflush.cc b/customext/cflush.cc
index 1a5cfa2d..8b72a97d 100644
--- a/customext/cflush.cc
+++ b/customext/cflush.cc
@@ -24,9 +24,9 @@ class cflush_t : public extension_t
 
   std::vector<insn_desc_t> get_instructions() {
     std::vector<insn_desc_t> insns;
-    insns.push_back((insn_desc_t){true, 0xFC000073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
-    insns.push_back((insn_desc_t){true, 0xFC200073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
-    insns.push_back((insn_desc_t){true, 0xFC100073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
+    insns.push_back((insn_desc_t){0xFC000073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
+    insns.push_back((insn_desc_t){0xFC200073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
+    insns.push_back((insn_desc_t){0xFC100073, 0xFFF07FFF, custom_cflush, custom_cflush, custom_cflush, custom_cflush});
     return insns;
   }
 
diff --git a/riscv/processor.cc b/riscv/processor.cc
index dd61caef..2cc1003a 100644
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@@ -961,7 +961,6 @@ void processor_t::register_base_instructions()
     extern reg_t rv64e_##name(processor_t*, insn_t, reg_t); \
     if (name##_supported) { \
       register_insn((insn_desc_t) { \
-        name##_supported, \
         name##_match, \
         name##_mask, \
         rv32i_##name, \
diff --git a/riscv/processor.h b/riscv/processor.h
index 96fdc54c..ec1b4007 100644
--- a/riscv/processor.h
+++ b/riscv/processor.h
@@ -29,7 +29,6 @@ reg_t illegal_instruction(processor_t* p, insn_t insn, reg_t pc);
 
 struct insn_desc_t
 {
-  bool supported;
   insn_bits_t match;
   insn_bits_t mask;
   insn_func_t rv32i;
@@ -39,9 +38,6 @@ struct insn_desc_t
 
   insn_func_t func(int xlen, bool rve)
   {
-    if (!supported)
-      return NULL;
-
     if (rve)
       return xlen == 64 ? rv64e : rv32e;
     else
@@ -50,7 +46,7 @@ struct insn_desc_t
 
   static insn_desc_t illegal()
   {
-    return {true, 0, 0, &illegal_instruction, &illegal_instruction, &illegal_instruction, &illegal_instruction};
+    return {0, 0, &illegal_instruction, &illegal_instruction, &illegal_instruction, &illegal_instruction};
   }
 };
 
diff --git a/riscv/rocc.cc b/riscv/rocc.cc
index 2d090952..f50934f0 100644
--- a/riscv/rocc.cc
+++ b/riscv/rocc.cc
@@ -32,10 +32,10 @@ customX(3)
 std::vector<insn_desc_t> rocc_t::get_instructions()
 {
   std::vector<insn_desc_t> insns;
-  insns.push_back((insn_desc_t){true, 0x0b, 0x7f, &::illegal_instruction, c0, &::illegal_instruction, c0});
-  insns.push_back((insn_desc_t){true, 0x2b, 0x7f, &::illegal_instruction, c1, &::illegal_instruction, c1});
-  insns.push_back((insn_desc_t){true, 0x5b, 0x7f, &::illegal_instruction, c2, &::illegal_instruction, c2});
-  insns.push_back((insn_desc_t){true, 0x7b, 0x7f, &::illegal_instruction, c3, &::illegal_instruction, c3});
+  insns.push_back((insn_desc_t){0x0b, 0x7f, &::illegal_instruction, c0, &::illegal_instruction, c0});
+  insns.push_back((insn_desc_t){0x2b, 0x7f, &::illegal_instruction, c1, &::illegal_instruction, c1});
+  insns.push_back((insn_desc_t){0x5b, 0x7f, &::illegal_instruction, c2, &::illegal_instruction, c2});
+  insns.push_back((insn_desc_t){0x7b, 0x7f, &::illegal_instruction, c3, &::illegal_instruction, c3});
   return insns;
 }